getting a string as the return value from a system command

[Catherine Moroney]

Hello,

I want to call a system command (such as uname) that returns a string,
and then store that output in a string variable in my python program.

What is the recommended/most-concise way of doing this?

I could always create a temporary file, call the "subprocess.Popen"
module with the temporary file as the stdout argument, and then
re-open that temporary file and read in its contents. This seems
to be awfully long way of doing this, and I was wondering about
alternate ways of accomplishing this task.

In pseudocode, I would like to be able to do something like:
hostinfo = subprocess.Popen("uname -srvi") and have hostinfo
be a string containing the result of issuing the uname command.

Thanks for any tips,

Catherine

 

[Robert Kern]

Hello,

I want to call a system command (such as uname) that returns a string,
and then store that output in a string variable in my python program.

What is the recommended/most-concise way of doing this?

I could always create a temporary file, call the "subprocess.Popen"
module with the temporary file as the stdout argument, and then
re-open that temporary file and read in its contents. This seems
to be awfully long way of doing this, and I was wondering about
alternate ways of accomplishing this task.

p = subprocess.Popen(['uname', '-srvi'], stdout=subprocess.PIPE,
stderr=subprocess.PIPE)
stdout, stderr = p.communicate()

--
Robert Kern

"I have come to believe that the whole world is an enigma, a harmless enigma
that is made terrible by our own mad attempt to interpret it as though it had
an underlying truth."
-- Umberto Eco

 

[Catherine Moroney]

Hello,

I want to call a system command (such as uname) that returns a string,
and then store that output in a string variable in my python program.

What is the recommended/most-concise way of doing this?

I could always create a temporary file, call the "subprocess.Popen"
module with the temporary file as the stdout argument, and then
re-open that temporary file and read in its contents. This seems
to be awfully long way of doing this, and I was wondering about
alternate ways of accomplishing this task.

p = subprocess.Popen(['uname', '-srvi'], stdout=subprocess.PIPE,
stderr=subprocess.PIPE)
stdout, stderr = p.communicate()

Thanks, I knew there had to be a more elegant way of doing that.

Catherine

 

[TomF]

Hello,

I want to call a system command (such as uname) that returns a string,
and then store that output in a string variable in my python program.

What is the recommended/most-concise way of doing this?

I could always create a temporary file, call the "subprocess.Popen"
module with the temporary file as the stdout argument, and then
re-open that temporary file and read in its contents. This seems
to be awfully long way of doing this, and I was wondering about
alternate ways of accomplishing this task.

In pseudocode, I would like to be able to do something like:
hostinfo = subprocess.Popen("uname -srvi") and have hostinfo
be a string containing the result of issuing the uname command.

Here is the way I do it:

import os
hostinfo = os.popen("uname -srvi").readline().strip()

(I add a strip() call to get rid of the trailing newline.)

os.popen has been replaced by the subprocess module, so I suppose the
new preferred method is:

from subprocess import Popen, PIPE
hostinfo = Popen(["uname", "-srvi"], stdout=PIPE).communicate()[0].strip()


Looks ugly to me, but there we are.

-Tom

 

[Robert Kern]

Hello,

I want to call a system command (such as uname) that returns a string,
and then store that output in a string variable in my python program.

What is the recommended/most-concise way of doing this?

I could always create a temporary file, call the "subprocess.Popen"
module with the temporary file as the stdout argument, and then
re-open that temporary file and read in its contents. This seems
to be awfully long way of doing this, and I was wondering about
alternate ways of accomplishing this task.

In pseudocode, I would like to be able to do something like:
hostinfo = subprocess.Popen("uname -srvi") and have hostinfo
be a string containing the result of issuing the uname command.

Here is the way I do it:

import os
hostinfo = os.popen("uname -srvi").readline().strip()

(I add a strip() call to get rid of the trailing newline.)

os.popen has been replaced by the subprocess module, so I suppose the
new preferred method is:

from subprocess import Popen, PIPE
hostinfo = Popen(["uname", "-srvi"], stdout=PIPE).communicate()[0].strip()


Looks ugly to me, but there we are.

The easy way to fix things that look ugly but are the right thing to do is to
wrap them up into a utility function and call the utility function everywhere.

--
Robert Kern

"I have come to believe that the whole world is an enigma, a harmless enigma
that is made terrible by our own mad attempt to interpret it as though it had
an underlying truth."
-- Umberto Eco